Get matched with top generator install pros in Alpha, IL

Q: How do I determine what size generator my house needs?

• <div><p>To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.</p><p>Here are some typical wattage requirements for common appliances:</p><ul><li><p>Refrigerator: 600 watts</p></li><li><p>Large dehumidifier: 700 watts</p></li><li><p>Large window air conditioner: 1,400 watts</p></li><li><p>Water heater: 3,000 to 4,500 watts</p></li><li><p>Electric furnace: 5,000 to 25,000 watts</p></li></ul><p>A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.</p><p>While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:</p><ul><li><p>1,000 sq ft: 6&ndash;9 kW</p></li><li><p>1,500 sq ft: 7&ndash;10 kW</p></li><li><p>2,000 sq ft: 10&ndash;14 kW</p></li><li><p>2,500 sq ft: 12&ndash;16 kW</p></li><li><p>3,000 sq ft: 16&ndash;20 kW+</p></li></ul><p>For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.</p></div>

Q: What size of diesel generator do you need to run a house?

• <div><p>Sizing a generator is a careful process that requires calculating the <a href="https://www.angi.com/articles/electrical-load-calculation.htm">electrical load</a> of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.</p><p>In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more. </p></div>

Q: How many days can a standby generator run continuously?

• <div><p>The <a href="https://www.angi.com/articles/how-long-can-whole-house-generator-run-continuously.htm">amount of time a standby generator can run continuously</a> is around <b>3,000 hours</b> on average. However, standby generators can generally run indefinitely as long as they have a continuous fuel supply. Generators hooked up to a home&rsquo;s natural gas supply are the best option for extended usage, as these won&rsquo;t rely on a finite fuel supply based on how much you have in storage. Generators running on liquid propane or diesel won&rsquo;t last as long, as these require fuel storage and regular refueling to stay running.</p></div>

Q: Is a natural gas generator less expensive than using electricity?

• <div><p>Natural gas and electricity rates vary significantly based on location, and pricing can change over time, too. It&rsquo;s possible that in locations where natural gas is particularly inexpensive, it will cost less than grid-based electricity will. However, you should also factor in the generator&rsquo;s initial costs and maintenance needs, as well as its noise level and if it can comfortably power all your home appliances.</p></div>

Q: What happens if my whole-house generator is too small for my AC?

• <div><p>An undersized whole-house generator has the potential to overheat and shut down when you try to run a central AC system. This scenario can not only damage the whole-house generator, but can also trip your home&rsquo;s breakers or cause electrical damage. To avoid this situation, hire a local generator installer to correctly size your whole-house generator.</p></div>

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Verified Reviews for Generator Install pros in Alpha, IL

*The Angi rating for Generator Install companies in Alpha, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

*The HomeAdvisor rating for Generator Install companies in Alpha, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

Last update on April 03, 2026

Reviewed in April 2026
I received a phone call within 48 hrs. Technician came out to give estimate within 24 hrs. Technician even temporarily patched area of metal roof (ridge cap) where hole was after hail/wind storm. Very reasonable price. The 2 men were considerate, polite, timely and professional. I did secure...
Moeller Construction
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Reviewed in November 2025
My pro, Bob, did an excellent job at installing my over the range microwave. He also removed and hauled away my old one. Bob was punctual, efficient, and talked me through the process of the exact work he would be performing. He was friendly and also cleaned up nicely when the job was complete....
Redemption Home Improvement LLC
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Reviewed in July 2025
The job that was done was fantastic. Brett Allen the installer was very efficient and had great knowledge of his job
Mad City Windows & Baths
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Reviewed in April 2025
These guys were great! We had snow breaks installed on our metal roof. These guys were fast and efficient, they were honest and fair. We waited a full year to give a review, to see how the snow breaks and the quality of their work held up. My entire family enjoyed watching the snow breaks work...
Quality Roofing Pro
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Reviewed in March 2025
Our Larson storm door closer was caught by the wind and ripped the bracket away from the exterior door frame. Chris Engle promptly arrived when he said he would. Polite and professional, he accessed the damage and told me what he could do on the spot for the least amount of money. Not a pretty...
Engle construction LLC
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Reviewed in October 2024
Great company prompt service was a little bit leery about going with the basic $9995 wet area but after the install seeing the product I must say I'm very very happy and pleased, would hire again. Amanda
American Bath Company
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Reviewed in August 2022
Excellent job with installation and providing instructions. The dogs have adapted to the fencing nicely.
Dog Guard
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Reviewed in December 2020
I had a great experience with Mas City windows and bath. They installed 7 windows in my house. From the guy who came and told us about the windows to the guys that came and installed them were all very knowledgeable answered every question I had. I am having them come back and do the rest of my...
Mad City Windows & Baths
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Reviewed in July 2019
The young men that installed our new roof were very professional. They worked hard the entire time and I enjoyed having there here at our home. The roof looks great and they cleaned up perfectly. They also stacked all the scrap wood for my bird house building.
Wilson Residential Construction Services, LLC
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Reviewed in September 2018
The finished product is great, but I would never use this company again, nor would I recommend them. When evaluating estimates, I was told that installation would begin about 4 weeks after I signed the contract. Installation wasn't complete until slightly more than 10 weeks after I signed...
M.C. Fence & Deck, LLC
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Find Generator install pros in Alpha

Tri-State Water, Power & Air

5.0(

)

Serving Alpha, IL and surrounding areas

Approved (Corporate)

In business since 1992

Free estimates

Emergency services offered

We are the experts in the field of Whole Home Generator Sales and Installation, with over 20 years of experience in the game.\nWe provide turn-key installation by licensed professionals - 24 hour emergency service - Remote Monitoring - Long term maintenance and service by factory trained technicians.

39 neighbors recently requested a quote

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Mid America Lightning Protection

4.5(

)

Serving Alpha, IL and surrounding areas

Approved

In business since 1969

Free estimates

Emergency services offered

"Responsive, fair pricing. Quality of installation could have been done a little better as rods were slightly crooked and they did not pull the wiring tout on top of house so not totally parallel to roof line."

+70

Response time6 hrs

Response rate94%

3 neighbors recently requested a quote

Serving Alpha, IL and surrounding areas

Approved

In business since 2009

Free estimates

Emergency services offered

"Joe, Mark, and Their Team did a Splendid Job for Us on this Business Phone Line Install. There are Very Knowledgeable and provided the Needed Assessment and "Fix" in a Very Timely Manner. I Highly Recommend Accent Tel USA! God Bless You! Philippians 1:3-6! Have a Wonderful Day in the Neighborhood & "Stay on the Nice List"! :)"

Response time3 hrs

Response rate99%

5 neighbors recently requested a quote

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Todd

New to Angi

Serving Alpha, IL and surrounding areas

Approved

Free estimates

Emergency services offered

Hello, I offer a multitude of services including handyman, cabinet installation, a multitude of repair and construction services, and more. Feel free to reach out to me to see if I can help you with whatever services you need completed.

2 neighbors recently requested a quote

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Power Services Company, LLC

5.0(

)

Serving Alpha, IL and surrounding areas

In business since 2010

Free estimates

Credit card accepted

"Very professional, the best generator company I have worked with."

Response time1 day

Recommended by100%of homeowners

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Empire Electric, Inc.

5.0(

)

Serving Alpha, IL and surrounding areas

In business since 2022

Credit card accepted

Offers commercial services

"Hardwired car charger and upgraded the fuse box. Nice people to work with. Cares about customers needs. Cost lower than other bids. Couldnâ t be more impressed with their service. Highly recommended. I will use them for any future electrical needs."

Response time11 hrs

Response rate100%

Recommended by100%of homeowners

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Lightning Defense, LLC (Illinois)

4.6(

136

)

Serving Alpha, IL and surrounding areas

In business since 1972

Free estimates

Emergency services offered

"John Sherlock and his wife are the consummate professionals! I would highly recommend them. Their attention to detail and installation quality, was superb. Johns knowledge of Lighting protection is apparent after 40+ years. You will not be disappointed . July 2020. D.Riggio Carterville, Illinois"

+13

Response time4 hrs

Recommended by100%of homeowners

Serving Alpha, IL and surrounding areas

In business since 2018

Free estimates

"We are very satisfied with Mike's service. Efficient, quick, did a total clean-up after he changed fans. Will definitely hire him again should I need an electrician."

Response time11 hrs

Recommended by95%of homeowners

Serving Alpha, IL and surrounding areas

In business since 2008

Emergency services offered

Credit card accepted

"They were informative! It's a family business that is generational in their craft. They explained my unit to me and gave me tips to improve it's care. I will be using them in the future for maintenance."

Recommended by82%of homeowners

Serving Alpha, IL and surrounding areas

In business since 2020

Emergency services offered

Credit card accepted

AIO provides computer support services for all PC platforms including Apple OSX/iOS, Microsoft Windows, and Google Android devices. \n\nWe are the only company on Angi.com with a BBB A+ rating providing nation-wide IT support on-site/remote services from over 1500 locations. You can call us directly at 832-402-1335, option 1 for sales, to be connected to a sales engineer if you need immediate help. You can also visit our website at https://aiosupport.net. We look forward to helping you!

Helping a Victim who was being Cyber-stocked

Recommended by91%of homeowners

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Showing 1-10 of 49

Generator Install questions, answered by experts

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

Refrigerator: 600 watts
Large dehumidifier: 700 watts
Large window air conditioner: 1,400 watts
Water heater: 3,000 to 4,500 watts
Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

1,000 sq ft: 6–9 kW
1,500 sq ft: 7–10 kW
2,000 sq ft: 10–14 kW
2,500 sq ft: 12–16 kW
3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.

In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more.

The amount of time a standby generator can run continuously is around 3,000 hours on average. However, standby generators can generally run indefinitely as long as they have a continuous fuel supply. Generators hooked up to a home’s natural gas supply are the best option for extended usage, as these won’t rely on a finite fuel supply based on how much you have in storage. Generators running on liquid propane or diesel won’t last as long, as these require fuel storage and regular refueling to stay running.

Natural gas and electricity rates vary significantly based on location, and pricing can change over time, too. It’s possible that in locations where natural gas is particularly inexpensive, it will cost less than grid-based electricity will. However, you should also factor in the generator’s initial costs and maintenance needs, as well as its noise level and if it can comfortably power all your home appliances.

An undersized whole-house generator has the potential to overheat and shut down when you try to run a central AC system. This scenario can not only damage the whole-house generator, but can also trip your home’s breakers or cause electrical damage. To avoid this situation, hire a local generator installer to correctly size your whole-house generator.

The Alpha, IL homeowners’ guide to generator installs

From average costs to expert advice, get all the answers you need to get your job done.

See all articles

Taylor Freitas
•
Apr 6, 2026Apr 6, 2026
How Much Does a Whole-House Generator Cost? [2026 Data]
The average cost of a whole-house generator falls between $5,000 and $25,000. Keep reading to learn how much you can expect to spend.
Alison Kasch
•
May 3, 2026May 3, 2026
How Much Does a Natural Gas Generator Cost? [2026 Data]
Natural gas generators are whole-home standby generators that are connected to your home’s natural gas line. The average cost for a natural gas generator is $12,000.
Alison Kasch
•
Apr 4, 2026Apr 4, 2026
How Much Does It Cost to Install a Generator Transfer Switch? [2026 Data]
The cost to install a generator transfer switch depends on several factors. Our guide will help you understand all of the costs.
Tyler Lacoma
•
May 21, 2026May 21, 2026
How to Use a Portable Generator: A Complete Guide
Portable generators are handy for many reasons, but they require care to prevent fire, electrocution, and more. Stay safe with this guide on how to use a generator.
Tyler Lacoma
•
May 3, 2026May 3, 2026
How Do Whole-House Generators Work?
Whole house generators are a power alternative that can deal with frequent blackouts and other problems. Here’s how they function.
Dan Simms
•
May 21, 2026May 21, 2026
How to Hire a Generator Installer
Generators should give you peace of mind, but you’ll only get that if your installer knows what they’re doing. Learn how to hire a pro and what red flags to look for.